Prior art fluted drill bits are designed to remove drilled material that is formed as the drill bit penetrates the material being drilled. Such bits have a sharp leading edge along the entire length of the flutes. Such bits may have one, two, three or more flutes. As a consequence of the sharp leading edge along the entire length of the flutes, the bit has a side-cutting ability which also extends the entire length of the flute, and if lateral or non-axial forces are imparted to the drill bit during drilling, this results in a non-circular widened or oval shaped hole as the drilled hole deepens, during manual or hand-held drilling. The developing of a widened or oval shape to the drilled hole is caused by the sharp leading edge along the entire length of the flutes, when the drill bit is being used to drill a hole, especially when used in manually drilling.
The departure from a true circular hole, i.e., the tendency to a widening or oval shaping of the hole results in a defininte disadvantage for applications that require a perfectly circular cylindrical hole such as is most important in bone surgery, especially in the mouth where drilling access is limited.
Accordingly, a need exists for a drill bit which avoids the cutting potential that is present from the leading cutting edges of almost the whole length of the flutes such as occurs with prior art drill bits; and that the side cutting capacity of the flutes of the drill bit be limited to an initial minimal length portion of the flutes of the drill bit.